<?php
/**
 * CBehavior class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CBehavior is a convenient base class for behavior classes.
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: CBehavior.php 3001 2011-02-24 16:42:44Z alexander.makarow $
 * @package system.base
 * @since 1.0.2
 */
class CBehavior extends CComponent implements IBehavior
{
    private $_enabled;
    private $_owner;

    /**
     * Declares events and the corresponding event handler methods.
     * The events are defined by the {@link owner} component, while the handler
     * methods by the behavior class. The handlers will be attached to the corresponding
     * events when the behavior is attached to the {@link owner} component; and they
     * will be detached from the events when the behavior is detached from the component.
     * @return array events (array keys) and the corresponding event handler methods (array values).
     */
    public function events()
    {
        return array();
    }

    /**
     * Attaches the behavior object to the component.
     * The default implementation will set the {@link owner} property
     * and attach event handlers as declared in {@link events}.
     * Make sure you call the parent implementation if you override this method.
     * @param CComponent $owner the component that this behavior is to be attached to.
     */
    public function attach($owner)
    {
        $this->_owner=$owner;
        foreach($this->events() as $event=>$handler)
        $owner->attachEventHandler($event,array($this,$handler));
    }

    /**
     * Detaches the behavior object from the component.
     * The default implementation will unset the {@link owner} property
     * and detach event handlers declared in {@link events}.
     * Make sure you call the parent implementation if you override this method.
     * @param CComponent $owner the component that this behavior is to be detached from.
     */
    public function detach($owner)
    {
        foreach($this->events() as $event=>$handler)
        $owner->detachEventHandler($event,array($this,$handler));
        $this->_owner=null;
    }

    /**
     * @return CComponent the owner component that this behavior is attached to.
     */
    public function getOwner()
    {
        return $this->_owner;
    }

    /**
     * @return boolean whether this behavior is enabled
     */
    public function getEnabled()
    {
        return $this->_enabled;
    }

    /**
     * @param boolean $value whether this behavior is enabled
     */
    public function setEnabled($value)
    {
        if($this->_enabled!=$value && $this->_owner)
        {
            if($value)
            {
                foreach($this->events() as $event=>$handler)
                $this->_owner->attachEventHandler($event,array($this,$handler));
            }
            else
            {
                foreach($this->events() as $event=>$handler)
                $this->_owner->detachEventHandler($event,array($this,$handler));
            }
        }
        $this->_enabled=$value;
    }
}
